Preparation of dicyano halo-ethane cyclic compounds



United States Patent PREPARATION OF DICYANO HALO-ETHANE CYCLIC COMPOUNDS lierome C. Westfahl, Cuyahoga Falls, Ohio, assignor to The B. F. Goodrich Company, New York, N. Y., a corporation of New York No Drawing. Application May 28, 1954, Serial No. 433,304

Claims. (Cl. 260-465) This invention relates to a novel method for the preparation of cyclic compounds having a l,1-dicyano-1-haloethane group directly attached to a ring carbon atom, and relates particularly to a method of preparing aromatic and heterocyclic compounds having a 1,1-dicyano-1-haloethane group attached directly to a ring carbon atom.

Disclosed in United States Patent application 380,123 and 380,124 filed September 14, 1953, by J. C. Westfahl, are methods for the preparation of aromatic and heterocyclic methylene malononitriles. These aromatic and heterocyclic methylene malononitriles are water-insoluble and readily susceptible to hydrolysis or hydration in alkaline solutions.

According to the method of this invention, aromatic and hcterocyclic methylene malononitriles are reacted with hypohalous acids, salts or esters thereof in an alkaline media to obtain aromatic and heterocyclic compounds having a 1,1-dicyano-l-halo-ethane group attached directly to a ring carbon atom.

The reaction of aromatic and hetercyclic methylene malononitriles with a hypohalite compound which is soluble in an aqueous alkaline media can be described generically as follows:

ON ON wherein R represents an aromaticor heterocyclic group; X represents bromine or chlorine; Y represents hydrogen;

are the following compounds:

Benzyl malononitrile; o,m and p-methyl benzyl malononitrile; 2,4-dirnethyl benzyl malononitrile; 2,4,6-trimethyl benzylmalononitrile; 2,5dimethylbenzylmalononitrile; 2-

naphthylmethylmalononitrile; 2 thenylmalononitrile; para methoxybenzylmalononitrile; 2,5 'dimethoxy benzylmalononitrile; 2 methoxy 5 chlorob'enzyl malononitrile; para hydroxybenzylmalononitrile; 1,3,5 trimethyl 2,4 bis(2,2 dicyanoethyl) benzene; 1,4-dimethoxy 2,5 bis(2,2 dicyanoethyl) benezene; 2-(2,2- dicyanoethyl) furan; p,p di(2,2-dicyanoethyl) di benzyl; 1 methylenecarboxy 3 hydroxy 4 (2,2 dicyanoethyl) benezene; 1 dimethylenecarboxy 4 (2,2 dicyanoethyl) benzene; 4 (2,2 dicyanoethyl) bibenzyl; 3(2,2 dicyanoethyl) 4 methylphenylnitromethane; p ethyl m. (2,2 dicyanoethyl) phenyl acetonitrile; p (2,2 dicyanoethyl) benzyl acetate;

sulfonic acid; 4-[p-(2,2-dicyanoethyl) phenyl1-3-butenoic acid and 4-[4-(2,2-dicyanoethyl) naphthyll-S-butenoic acid and the like.

Among the hypohalous acids, alkali and. alkaline earth metal salts of hypohalous acids, and alkyl esters of hypohalous acids are included, by way of example, the following compounds:

Hypochlorous acid, hypobromous acid, sodium hypochlorite, sodium hypobromite, calcium hypochlorite, calcium hypobromite, potassium hypochlorite, methyl hypo chlorite, ethyl hypobrornite, propyl hypochlorite, propyl hypobromite, butyl hypochlorite, butyl hypobromite and;

the like. 7

The proportions of hypohalous acid and aromatic or heterocyclic methylene malononitrile can be varied Widely in the practice of this invention, although it is desirable that molar equivalents of the cyclic methylene malononitrile and hypohalite or a slight molar excess of hypo halite be employed.

The temperature at which the reactions of this invention can be carried out can be varied over a wide range, but preferably the reaction should be carried out at temperatures of about 20 C. to 20 C. in order to avoid decomposition of the hypohalite compounds since said compounds decompose in basic solutions at elevated temperatures.

In carrying out the reactions of this invention it is very desirable that the hypohalite compounds be brought in contact with the dissolved or alkaline solutions of the cyclic methylene malononitriles within a short period of time after the cyclic methylene malononitrile has been added to the aqueous alkaline solution, since as is pointed out hereinbefore, the nitrile groups of the :malononitriles are readily susceptible to hydrolysis.

The following examples are illustrative of the method of carrying out the reactions of this invention, and although they are specific in reference to the operating conditions, it is not intended that the patent should be limited thereto, for of course there are numerous means which are equivalent, which will be apparent to one skilled in the art. In all of the following examples all parts are by weight unless otherwise specified.

EXAMPE I 262 parts (0.185 mol) of a 5.25% aqueous solution of sodium hypochlorite was charged in a 1-liter 3-neck glass flask fitted with a thermometer and a stirred. A mixture of 10 parts sodium hydroxide, parts of water and 20 parts of 2,5-dimethoxy benzyl malononitrile was warmed until the solid dinitrile was essentially dissolved. The flask containing the sodium hypochlorite solution was cooled to 7 C. and the nitrile in solution in the sodium hydroxide was poured rapidly with stirring into the reaction flask. The reaction went to completion in about 2 minutes. The reaction products were diluted with Water, and the mixture was filtered with suction. A light yellow solid was recovered, washed with cold water, dried in vacuo to yield 20.04 parts (85.1%) of crude 2,'5-dimethyoxybenzylchloromalononitrile having the following structural formula 3 and having a meltingpoint. of .5l.5. to 52.5 C. The product was analyzed for carbon, hydrogen, nitrogen and chlorine content, and the analysis follows: Theory Found Theory Found Percent; Carbon 56. 33 56. 47, 56. 39

Percent Hydrogem 4. 72 4. ,4.

, Percent Nitrogen 10. 11 00 PercentCarbom... 57.49- 57.40,57.36 Percent'Bromin 28. 82 29. 03, 2s. 92 Percent Hydrogen. 4.42 4.43, 4.44 Melting Point 95.5-96.5 Percent N itrogen 11. 18 11.20 Percent Chlorine 14. 14 13. 67

- VI. 4-meth0xybenzylbromomalononitrile EXAMPLE II A S-neck glass flask fitted with a thermometer, a glass Theory Found stirringirod, and -a dropping tunnel was charged with 16'."15 par ts' of sodium hydroxide and 190-parts of water. $113, 2 33,; 1, 31 The fl'ask was cooled below 5 C. and 21.5 parts (0.135 gercenz llglitrogenn g 30 29 2g mol)'of"brornine was added. dropwise at a rate such, 55,3 ggt fff; j 3 5 that the t'emperatureremained below 5 C. A mixture comprising 210 parts of water and 21 parts of sodium hydroxideiwas' added to 21 parts 0134541101 of'ben- I EXAMPLES VII AND VH1 zylmalononitrile. The mixture was stirred and when the Reaction of heterocyclic methylenemalononitriles with solid benzylmalononitrile was almost completely dishypochlorite, compounds according to the method desolved the solution was added through the funnel to the scribed in Example I gives in good yields heterocyclic sodium hypobromite solution over an interval of about compounds having a l,l-dicyano-l-chloroethane group 3 minutes. The reaction product, a slurry of yellow 25 attached directly to a ring carbon atom. Set out in the solid, was diluted with equal volume of cold water following table are heterocyclic methylene malononitrile and filtered with suction. The solid was washed with compounds which react with hypochlorite compounds and cold water, dried in vacuum, purified by recrystallizathe products obtained thereby.

Reactant Product VII 0N 2-(2,2-dicyano ethyl) furan (IDN --CHzO-H' 2-(2',2,2-dieyan0-ehloro ethyl) CHzC-Cl 0 I furan 0 ON ON VIII ON 2-(2,2-d icyano ethyl) thlophene (IEN -CH2C-H 2-(2,2,2dicyan0-chlor0 ethyl) 0H2G'C1 S thiophene S 0N ON tion from hexane and 15.8 parts of benzylbromo- The reaction of heterocyclic methylene malononitriles malononitrile was recovered. The product was analyzed 40 of Examples VII and VIII with "hypobromites, in acfor melting point, carbon, hydrogen, nitrogen and brocordance with the method of Example I will produce mine, and. the analysis is as follows: bromo-compounds corresponding to the products obtained w in Examples VII and VIII. The reaction of aromatic Thcoyy Found and heterocyclic methylene malononitriles with low moo lecular weight alkyl hypohalites, such as methyl hypo- PercentCarbon 51.08. 51.26;51.24 chlorite, in accordance with the procedures described gggggg g tgggggn 2 83 3.00, hereinbefore, produces in good yield aromatic and hetero- ?drcent Bronine 34.00 34.213413 cyclic compounds having a 1,l-dicyano-l-halo-ethane Melting Pom group attached'to a ring carbon atom.

00 p n The methods employed in carrying out the reactions EXAMPLES 111 To VI of this invention are eificient for preparing cyclic com- The following compounds were prepared in accordance pounds having a 1,l-dicyano-l-halo-ethane group attached with the methods disclosed in Example I: benzylchlorodirectly to. a ring carbon atom wherein the halogen is malononitrile; 2,4,6-trimethylbenzylchloromalononitrile; characterized by acting as a positive halogen. These 01) 2,4,6 trimethylbenzylbromomalononitrile; 4 methoxycompounds are readily hydrolysed in aqueous solution benzylbromomalononitrile. Determination of melting and can be employed in solution as bactericidal formulapoi'nts and carbon, hydrogen, nitrogen and halogen contions. tentwas carriedout and is set out in the following table: From the foregoing it is readily apparent that the novel III. Benzylchloromalononitrile cyclic 1,l-dicyano-l-halo-ethane compounds of this in- 4 vention'can be prepared with little difiiculty, Various modifications and. deviations from the methods disclosed p V m herein will be readily apparent to those skilled in the g: gg art, therefore it isnot intended that he invention be 1&8 18 limited solely thereto, but only in accordance with the inn-1119mm, of and pp claims- I claim: 1V. 2,4,d-trimethylbenzylchloromalononitrile l. The method which comprises reacting a compound 7 having the formula R-CH2CH(CN)2 in which R Theory Fmmd is selected from'the class consisting of monocyclic and I p p bicyclic-aromatic rings, 'furan and thiophene rings, with g: @1 22: a water soluble. alkaline hypohalit e in which the halogen Percent Nitrogen 13.04 12.07 1s:selected'-romthe class COnS1SlZ1I1g.'Qf chlorine and 24 12- 3 bromine to; form a compound having the formula R- -CH2-=CX.(CN )2 wherein R has the; same designation as above and X is selected from the class consisting of chlorine and bromine.

2. The method which comprises reacting a compound having the formula R-CHz-CH(CN)2 in which R is selected from the class consisting of monocyclic and bicyclic aromatic rings and furan and thiophene rings with a hypohalite in an aqueous alkaline solution to form a compound having the formula R-CH2CX(CN)2 wherein R has the same designation as above and X is selected from the class consisting of chlorine and bromine.

3. The method which comprises reacting a compound having the formula R-CH2-CH(CN)2 in which R is selected from the class consisting of monocyclic and bicyclic aromatic rings and furan and thiophene rings with a hypobromite in an aqueous alkaline solution to form aromatic and heterocyclic compounds having the formula RCH2CX(CN)2 wherein R has the same designation as above and X is bromine.

4. The method which comprises reacting a compound having the formula R-CH2CH(CN)2 in which R is selected from the class consisting of monocyclic and bicyclic aromatic rings and furan and thiophene rings with a hypochlorite in an alkaline solution to form aromatic and heterocyclic compounds having a References Cited in the file of this patent UNITED STATES PATENTS Dosser et al July 1, 1952 OTHER REFERENCES Clark: 26 Chem. Abst., page 1561 (1932).

Leulier et al.: 34 Chem. Abst., col. 78 (1940). Hopkins et al.: 41 Chem. Abst., col. 734 (1947). Derbyshire et al.: 45 Chem. Abst., col. 9495 (1951). 

1. THE METHOD WHICH COMPRISES REACTING A COMPOUND HAVING THE FORMULA R-CH2-CH(CN)2 IN WHICH R IS SELECTED FROM THE CLASS CONSISTING OF MONOCYCLIC AND BICYCLIC AROMATIC RINGS, FURAN AND THIOPHENE RINGS, WITH A WATER-SOLUBLE ALKALINE HYPOHALITE IN WHICH THE HALOGEN IS SELECTED FROM THE CLASS CONSISTING OF CHLORINE AND BROMINE TO FORM A COMPOUND HAVING THE FORMULA R-CH2-CX(CN)2 WHEREIN R HAS THE SAME DESIGNATION AS ABOVE AND X IS SELECTED FROM THE CLASS CONSISTING OF CHLORINE AND BROMINE. 